It is known in portable radios to provide a receptacle on the radio housing for connection of external circuits to the radio. Such a receptacle is described in U.S. Pat. No. 3,812,310, issued May 21, 1974, to Bernard Gasparaitis, and assigned to Motorola, Inc. The plug connector which is used with this receptacle must have a long center conductor so that it can be inserted in the receptacle to operate the contacts thereof and complete the external connection thereto. This is not suitable for use with a very small hand-held radio device which may be used in a compact carrying housing as there is not adequate room for inserting the receptacles. Further, the connector design (long stem) does not lend itself to automatic methods of interconnect.
Further, known connector constructions have caused impedance discontinuities which have resulted in signal loss and caused distortion of the signal. Although prior connector and receptacle structures may perform well at audio frequencies, there is severe mismatch at VHF and UHF radio frequencies.